Given a square matrix and the task is to check the matrix is in lower triangular form or not. A square matrix is called lower triangular if all the entries above the main diagonal are zero.
Examples:
Input : mat[4][4] = {{1, 0, 0, 0},
{1, 4, 0, 0},
{4, 6, 2, 0},
{0, 4, 7, 6}};
Output : Matrix is in lower triangular form.
Input : mat[4][4] = {{1, 0, 0, 0},
{4, 3, 0, 1},
{7, 9, 2, 0},
{8, 5, 3, 6}};
Output : Matrix is not in lower triangular form.
Java
// Java Program to check for// a lower triangular matrix.import java.io.*;class Lower_triangular{ int N = 4; // Function to check matrix is // in lower triangular form or not. boolean isLowerTriangularMatrix(int mat[][]) { for (int i = 0; i < N; i++) for (int j = i + 1; j < N; j++) if (mat[i][j] != 0) return false; return true; } // Driver function. public static void main(String args[]) { Lower_triangular ob = new Lower_triangular(); int mat[][] = { { 1, 0, 0, 0 }, { 1, 4, 0, 0 }, { 4, 6, 2, 0 }, { 0, 4, 7, 6 } }; // Function call if (ob.isLowerTriangularMatrix(mat)) System.out.println("Yes"); else System.out.println("No"); }}// This code is contributed by Anshika Goyal. |
Output:
Yes
Time Complexity: O(n2), where n represents the number of rows and columns of the matrix.
Auxiliary Space: O(1), no extra space is required, so it is a constant.
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